Looking at the census entry which seems to read Rasville, I think it actually says Hasville too, with a slightly odd letter H. Been wondering whether Hasville might have been Decazeville, a commune in the Aveyron department in the Occitanie region in Southern France which was a centre of iron working. See this reference online in 'An Economic History of Modern France' by Francois Caron:
"However, in the 1820s there arose some big companies, usually societies anonymes, which tried to adopt all the English innovations, such as coke smelting, puddling, and rolling, at the same time (Terrenoire, Le Creusot, Alais, and Decazeville)."
Another reference in 'Mastering Iron: The Struggle to Modernize an American Industry, 1800-1868 by Anne Kelly Knowles:
"At Decazeville and the other company towns built by Cabrol's firm, virtually all of the engineers, puddlers, heaters, rollers, and polishers during the early years of production were immigrants from Wales. Some went home after a few years or emigrated to the United States. Others married French women and settled in as permanent residents."
This is only a hunch but might still be worth following up. Maybe someone could advise you on birth records for that area of France? Perhaps consider getting this post moved to the Europe board?
Drosybont
